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But. Ob 


Bulletin No, 65 Maren s Lees, 


Wy oR RIOT. 
M. M. LEIGH C}/\ 


COLLIONWEALTH OF PENNSYIVANTA 
DEPARTITENT OF INTERNAL 2PPAIRS 
James I, Woodward, Secretary 


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BUREAU OF TOPOGRAPHIC AND GEOLOGICAL SURVEY 
George H. Ashley, State Geologist 





LEAD AND ZINC ORES IN BLAIR COUNTY, PENNA, 


By 


Benjamin LeRoy Miller. 


Location. 


Although Pennsylvania is not now a producer of lead or Zine ore 
there have been times when the output of this State was important, 
At the present time when recently organized companies are seeking 
capital to re-open old mines, information about the deposits that once 
were mined with some success mav be particularly useful, 


The lead and Zinc “deposits or Blair County are confined to 
Sinking Valley which extends from Little Juniata River in a southwest- 
erly direction about ten miles, fMTwo mountain ridges of sandstone 
flank the limestone valley on the northwest and southeast, and, unit- 
ing just’ east of Altoona, close the south end of tne valley. The 
limestones of the valley belong to the great Cambro-Ordovician lime- 
stone. series. The valley is about five miles wide along the Little 
Juniaté but gradually narrows as the bounding ridges come closer 
toge ther, 


Within the limestones of the valley lead and zinc minerals have 
been found in many places, Much prospecting seems to indicate that 
the only localities which might justify the expenditure of money and 
effort in the search for ore are in the two ends of the valley. These 
are the only places where mining has been carried on, The chief ore 
bodies are those about one-fourth mile southwest of Birmingham Station, 
east of Tyrone. Others are near the end of the valley called the 
"Nettle" east of Altoona, 


tt ar eee meee 





i matt, Prenklin, Zine and lead‘devosits of the Sinking Valley, 
Second Pennsylvania Geol, Survey, Vol. T, pp. 247-277, 1881 





History or ilining Operations. 


The first:lead and zine’mines of Pennsylvania were operated in the 
Sinking Valley, Blair County, during the Revolutionary Wars. tne 
Continental Army being in great need of lead for bullets, a party was 
Sent to investigate some lead deposits said to be in the ‘Wildermess 
near Frankstown, As a result of the exsminition General Daniel 
Roberdeau opened and worked some shollow mines in the southern end of 
Sinking Valley during 1778 and 1779, Several letters from General 
Roberdenu and others concerning these operations-are in the Pennsylvania 
Archives (First Series) especially an Vols: 6, ae and 8. At one time 
1,000 pounds of lead was sold to the State at $6.00 a pound in the 
depreciated currency of that period. It is not known when the mines 
closed but probably the operations were short-lived because of the 
expense of transporting materials for mining and smelting the ore, the 
maintanance of the laborers in the Wilderness, as it was called, and 
the guards that were necessary on account of hostile Indians. 


The next period of active mining was in 1795 when John Ifusser was 
employed by Robert Morris to drive a drainage tunnel into the side of 
the hill near Birmingham to connect with a shaft previously sunk. No 
further information is available concerning this undertaking, 


It seems that there was little if any more work done until 1864 
when the Keystone Zine Company was organized and with abundant capital 
Started operations on a large scale, Most of the work was done in the 
northern part of the valley-near Birmingham but investigations by this 
Company and others were made in a number of places in the southern part 
of the valley.- New shafts and tunnels were driven and a large reducing 
plant for the manufacture of 2ine oxide was built near Birmingham for 
the treatment of ores from this and other regions, In this attempt the 
principal attention was given to zinc while in the previous operations 
only lead was sought and the Zinc minerals present were regarded as 
worthless or as part of the gangue. After six years, during which 
several thousand tons of ore were mined, the company became financially 
involved and the plant was closed in 1870; Since that time there have 
been sporadic efforts to discover workable ore beds in various parts of 
the valley but with indifferent success, In 1875 some diamond drill 
boring was done in the southern part of the valley and in 1876 a small 
quantity of ore from another property was mined and shipped to the 
Bamford reduction plant near Lancaster, 


The latest known attempt to re-open the mines was in 1901 when a 
certain company issued a orospectus and endeavored to interest capital 
in the project. This is said to have been merely a stock-selling scheme, 


At present the mines are in bad condition although the writer was 
able to go down one of the old shafts near Birmingham in the summer of 
1921 and to see something of the old drifts and stopes that are above 
water level, 


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Occurrence and Character of the Ore. 


The dolomitic limestone strata of Sinking Valley form a slightly 
overturned anticlinal fold that extends throushout the valley with the 
axis pitching to the southwest. The close folding has shattered the 
rocks and metal-bearing solutions have deposited the lead and Zinc 
Ores in the crevices. 


In the Birmingham region where a number of shafts were sunk and 
an adit driven 347 feet into the side of the hill only one important 
vein seems to have been encounterec, although there were many cross 
veins and off-shoots. This vein seemed to‘parallel the strike of the 
enclosing limestone strata, about N, 65°H,, and was near the crest of 
vhe anticlinal fold. Slickensides were observed on the ore and the 
wall rocks, showing movement subsecuent to the deposition of the ore. 
One drift 167 feet long followec a vein said to have averaged somewhat 
more than seven feet in thickness. No statement is given as to the 
relative proportions of gangue and ore minerals, 


In the south end of the valley the veins cut across the strata, 
llany were prospected over a consiacerable area but it is said that few 
were more than six inches wide, although one was found with a width of 
14 inches, Again no data concerning the constitution of the veins are 
available, : 


The ‘ores consisted primarily of sphalerite and galena with - 
dolomite, barite, pyrite, and "no inconsiderable amount of brown, 
highly ferruginovs, argillaceous matter." in the Birmingham region 
the zine ore predominatec whereas the ores near the "kettle" contained 
more lead; in some cases the lead content exceeded that of Zinc. 
Smithsonite, calamine and cerusite were found in the upper levels. 


ik *- ia) J ox) * + * 
Platt” gives the following analvses of ore from the Birmingham 
shafts. 


Analyses of Zine Ore from Birmingham, Blair County, Penna. 








Sr os 4,53 9,67 9.67 6.90 
Carbonic acid £7480 29 SO Lo..UD a0.Oo 
tide of cadmiun 1.84 
Mice eo. sine 46495 54,50 OLS LG 47450 
Lime £448 11,08 gh ae 
Sulphur eee: veh wee Pee es 
Lead’ 544 Mg ey ao Lee 
Iron, magnesia 

and water LOWE 14,01 Ds Oo 13,56 
ek 


Place, Franklin: ops cit. 





: 

Another writer states that "the ore of Sinking Volley, Pennsyl- 
vania, treated at the seystone Works, contained, commonly, 6 to 8 per 
cent galenite and gave an oxide with 25,084 per cent lead sulphate, 
73,246 Zine oxide, and 0.574 zine sulphate.” 


Production. 


Platt says that more than 2000 tons of ore were mined by the 
xeystone Company. This probably represents the greater part of all 
the ore that has been obtained from all the workings in Sinking Valley. 


Future Prospects. 


The present inaccessibility of the old mines prevents forming 
délinite Conclusions concerning the nature anc, extent of the remaining 
Ore bodies. When the mines were closed in 1870 tne prevailing opinion 
Seemed to be that the best of the ores were exhausted. In view of the 
fact that extensive prospecting had been done in many places both by 
Sinking shafts and by diamond drilling it does not seem probable that 
the district possesses much merit as a lead or Zinc producer, 





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